Thesis (MScFoodSc) Stellenbosch University, 2014 / ENGLISH ABSTRACT: We aimed to determine how canopy position influences fruit quality and consumer preference for
the eating quality and appearance of ‘Forelle’, ‘Bon Chrétien’ and ‘Bon Rouge’ pears. Our
hypothesis was that consumer preference would be higher for the appearance and eating quality of
outer canopy fruit.
Our first trial investigated the effect of canopy position and cold storage duration on quality
attributes and consumer preference for ‘Forelle’ pears. Mealiness was much more prevalent in
outer canopy fruit in 2012 and after 9 and 12 weeks cold storage in 2011. In 2011, consumers
preferred the eating quality of inner canopy pears that had been subjected to 12 and 16 weeks of
cold storage while inner canopy pears were generally preferred in 2012. This study provides
support for the mandatory 12 weeks cold storage of ‘Forelle’ pears.
Our second trial investigated the effect of canopy position and harvest maturity within the
commercial picking window on the quality attributes and consumer preferences for ‘Forelle’ pears.
Inner canopy pears of harvest 1 (23 February) and harvest 2 (27 February) were significantly
preferred in terms of eating quality. The general dislike for harvest 3 (13 March) pears and outer
canopy fruit seemed to relate to an incidence of mealiness. Our results suggest that harvesting
‘Forelle’ pears at a firmness ≈6.2 kg will ensure that both inner and outer canopy pears have
acceptable eating quality.
In our third trial, fruit were harvested at commercial firmness from two orchards in each of Elgin
and Ceres to assess the effect of orchard site on quality attributes of ‘Forelle’ pears. Total soluble
solids (TSS) were higher in Elgin while flavour attributes were more pronounced in Ceres. In both
areas, outer canopy pears were higher in TSS and lower in titratable acidity (TA) but canopy
position had no effect on sweet and sour taste. Mealiness incidence was high in outer canopy fruit
from Elgin, as well as in one Ceres orchard. Further research over consecutive seasons is needed
to determine the reasons for orchard differences in mealiness incidence.
Our fourth trial investigated the effect of canopy position on quality attributes and consumer
preference for ‘Bon Chrétien’ and ‘Bon Rouge’ pears. Despite a higher TSS:TA ratio in outer
canopy ‘Bon Rouge’ pears and a higher TSS and dry matter concentration in outer canopy ‘Bon
Chrétien’ pears, canopy position did not affect sensory eating quality attributes. Seen overall,
results indicate that canopy position has a minor effect on consumer preference for ‘Bon Chrétien’
and ‘Bon Rouge’ eating quality.
No significant differences in colour and consumer preference for appearance were found between
outer and inner canopy ‘Bon Chrétien’ pears. Consumers slightly preferred the redder outer
canopy ‘Bon Rouge’ pears over the less red inner canopy fruit. Although consumers preferred the
red blush colour of outer canopy ‘Forelle’ pears, inner canopy pears also received high scores.
Inner canopy ‘Forelle’ pears should not be viewed as inferior to outer canopy fruit with regard to
both eating quality and appearance. / AFRIKAANSE OPSOMMING: Ons het gepoog om die effek van boomposisie op vrugkwaliteit en verbruikersvoorkeur vir die eetkwaliteit en voorkoms van ‘Forelle’, ‘Bon Chrétien’ en ‘Bon Rouge’ pere te ondersoek. Ons hipotese was dat verbruikersvoorkeur hoër sou wees vir die voorkoms en eetkwaliteit van pere van die buitekant van die boom se blaredak.
Ons eerste proef se doelstelling was om die effek van boomposisie en koelopberging op die kwaliteitseienskappe en verbruikersvoorkeur vir ‘Forelle’ pere te bepaal. Melerigheid was beduidend meer aanwesig in buitevrugte in 2012 asook na 9 en 12 weke koelopberging in 2011. Verbruikersvoorkeur vir eetkwaliteit was die hoogste vir binnevrugte na 12 en 16 weke koelopberging in 2011 terwyl binnevrugte in die algemeen voorkeur geniet het in 2012. Hierdie studie steun die bevindinge van vorige studies dat ‘Forelle’ pere vir ten minste 12 weke koelopgeberg moet word.
Die doel van ons tweede proef was om te bepaal of ‘Forelle’ pere wat by verskillende ryphede binne die kommersiële oesperiode geoes is, verskille toon in kwaliteitseienskappe en of hierdie verskille, indien enige, verband hou met verbruikersvoorkeur vir eetkwaliteit. Die eetkwaliteit van binnevrugte van oes 1 (23 Februarie) en oes 2 (27 Februarie) is verkies bo buitevrugte. Die algemene afkeur vir oes 3 (13 Maart) en buitevrugte kan moontlik toegeskryf word aan die hoë voorkoms van melerigheid. Ons resultate dui aan dat beide binne- en buitevrugte aanvaarbare eetkwaliteit behoort te hê indien ‘Forelle’ pere by ‘n fermheid van ≈6.2 kg geoes word.
Vir ons derde proef is ‘Forelle’ pere geoes by kommersiële fermheid (≈6.4 kg) vanaf twee boorde in elk van Elgin en Ceres. Totale opgeloste vastestowwe (TOV) was hoër in Elgin pere terwyl geur-eienskappe meer prominent was in Ceres pere. In beide areas het buitevrugte hoër TSS en laer titreerbare sure (TS) gehad, maar boomposisie het egter geen effek op soet en suur smaak gehad nie. Die voorkoms van melerigheid was hoog in buitevrugte van die Elgin boorde, sowel as in een van die Ceres boorde. Verdere navorsing oor opeenvolgende seisoene word benodig om redes vir die verskille in die voorkoms van melerigheid tussen boorde te ondersoek.
Die doelstelling van ons vierde proef was om die effek van boomposisie op die kwaliteitseienskappe en verbruikersvoorkeur vir ‘Bon Chrétien’ en ‘Bon Rouge’ pere te ondersoek. Ondanks ‘n hoër TOV:TS ratio in ‘Bon Rouge’ buitevrugte en ‘n hoër TOV en droë massa konsentrasie in ‘Bon Chrétien’ buitevrugte, het boomposisie ‘n minimale impak gehad op sensoriese eetkwaliteitseinskappe en verbruikervoorkeur vir die pere.
Boomposisie het geen effek op die kleur en verbruikersvoorkeur vir die voorkoms van ‘Bon Chrétien’ pere gehad nie. Verbruikers het ‘n effense hoër voorkeur getoon vir die rooier ‘Bon Rouge’ buitevrugte. Alhoewel verbruikers die aantreklike rooi bloskleur van ‘Forelle’ buitevrugte verkies het, het die groen tot geel binnevrugte ook hoë voorkeurpunte behaal. Rakende voorkoms en eetkwaliteit, is ‘Forelle’ binnevrugte glad nie minderwaardig teenoor buitevrugte nie.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/86367 |
| Date | 04 1900 |
| Creators | Cronje, Arina |
| Contributors | Steyn, W. J., Muller, M., Theron, K. I., Crouch, E. M., Stellenbosch University. Faculty of AgriSciences. Dept. of Food Science. |
| Publisher | Stellenbosch : Stellenbosch University |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | English |
| Type | Thesis |
| Format | viii, 163 p. : col. ill |
| Rights | Stellenbosch University |
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